SohCahToa

[wiishesssss]

I'm actually looking for an explanation.


given triangle ABC w/ Measure of angle c = 90 degrees
if a = 3 and c = 5 ...

b = 4

so Measure of angle A and measure of angle B = 90 degrees
(or they are complementary)

so, c = 5 (hypotenuse) ; b = 4 (adjacent) ; a = 3 (opposite)

i understand using SohCahToa ..
and that
Sin A = 3/5 ; Cos A = 4/5 ; Tan A = 3/4

but why is it that sin B = 4/5 ; cos B = 3/5 ; tan B = 4/3


an explanation for this would be great
(also i'm sorry that i couldn't get an actual picture of the triangle up on here)

 

[mammothrob]

Looking at the triange will help in making this come togeather for you.


If you draw a line out of any angle you get reach the side oppisite of it and which coorisponds to it in sohcahtoa. B is across from side b and so on.

SinB= Oppisite/Hypotensue
what is oppisite of angle B? side b which you said is 4
the hypotenuse is 5 right?
SinB=4/5